I think cops should be shooting people that assault them more often than they do... regardless of how 'easy' absent civilians think it might have been to take one action or another instead of shooting to kill.
Attack a cop for any reason, with or without any weapon of any kind, and you get shot. That should be the law. Physically attack a cop and you die.
Although I can appreciate your results oriented mind-set, (look for the positive, they tell me), too many non-cops would be unnecessarily killed than they would otherwise; moreover, and unfortunately, less cops would be harmed, and I know that's negative and an unacceptable attitude (but take a balanced approach, they tell me).
Even if by chance you have good intentions, barbarically taking the life of others isn't necessary to exact change. That's not to say we can't add an appalling element of incivility to the equation. For instance, we could beat a loved one for each instance of violence against an officer. After the officer puts his own life in danger by never using a gun unless a gun is clearly involved (and more cops will get hurt, but that's okay ... most will live), someone, usually a parent of the person who attacked the cop will be selected, located, and taken into custody for a public beating. It doesn't have to be brutal, just hurtful. Of course, this will only be in conjunction with a country wide initiated program in public schools across the nation teaching children and young adults that we will no longer limit punishment to the wrong-doers but also to the people in their lives one would reasonably think they would ordinarily care about. Is it wrong and unfair? Absolutely, but remember, 1) less non-cops would be shot, and 2) more cops would be harmed. Can't we sacrifice some civility for that?
Under your proposal, many people will be outraged and killed. Under my alternative fantasy proposal, many people will be outraged yet not killed. If anyone thinks the killings under my proposal will result in more deaths through revolt, they are forgetting about how gradual shifts in mindset can lead people to endure a reign of rule akin to evil kings of centuries past. Of course, we'd probably have to end the internet and global communication before stomping out liberal minded uprisings, but hey, I never said it would be easy, but hey hey, less deaths.
But wait, is that a life worth living? Nay, probably not. Don't get me wrong, I think some incivility may not be as bad as one might think, but both your plan and mine are examples of extremism that has no place in today's world--even if we could pull it off. Emotion may fuel our desire to bring about immediate and poignant change, but our intellect must intercede to bring reasoned and just action, even if the results are less than ideal, for how we go about doing what we can plays an enormous moral role in doing the things we can.